Giovanni Battista Grillo (late 16th century–mid-November 1622) was an Italian composer and organist.
Little is known about Grillo until he was elected organist to the Venetian confraternity 'Scuola Grande di S Rocco' on 28 August 1612. This was a prominent position in the musical life of the city. In addition he was appointed first organist of San Marco on 30 December 1619. He died in Venice.
His music follows Giovanni Gabrieli, especially his Sacri concentus ac symphoniae (Venice 1618) which includes vocal canzonas up to 12 parts, using cori spezzati. He is also known for three instrumental canzonas published in Raveri's collection Canzoni per sonare con ogni sorte di stromenti (Venice, 1608).
Arnold, D: 'Grillo, Giovanni Battista', Grove Music Online ed. L. Macy (Accessed 28 Dec 2007)